Connector assembly



ATTORNEY mww m m w -GE MW}U m m 2,. NN on 2 mm m 1 nw l E 1 v/ -11 Lw {a L B x E \\\v\ \K \K ow s m. 2 x 2 @N 2 n m Q 6 Oct. 30, 1962 F. c. WHEELER ET AL CONNECTOR ASSEMBLY Filed Dec. 21, 1960 United States Patent 3,061,7114 CONNECTOR ASSEMBLY Floyd C. Wheeler, Acton, and Thomas E. Finch, Shelbyville, Ind, assignors to General Electric Company, a corporation of New York Filed Dec. 21, 19611, Ser. No. 77,413 4 Claims. (Cl. 2119-26) This invention relates primarily to electrically powered hand tools, and more particularly to an arrangement for electrically and mechanically connecting an electrically heated tip in its supporting handle.

In electrically powered tools such as soldering irons, the tool tip is subjected to wear and frequently needs to be removed for cleaning or replacement, or for the substitution of a different type tip. It is therefore the main object of this invention to provide a construction for electrically connecting and mechanically supporting an electrically powered tool tip such that its removal and replacement may be made quickly Without the use of tools and without any resulting damage to the tip or other parts of the tool.

A further object of this invention is to provide a simple, reliable and relatively inexpensive connecting device which has improved electrical and mechanical characteristics and which minimizes the heat transfer to the handle.

Another object of this invention is the provision of an improved resilient support for a removable work tip resulting from a unique construction for connecting the work tip to the handle.

Further objects and advantages will become apparent from the accompanying drawing, in which there is illustrated a preferred embodiment of our invention, and the invention will be better understood from the description below. The features of novelty which characterize this invention are set forth in the claims attached to and forming part of this specification. While these illustrations have been chosen to best present what we believe to be the preferred embodiment of this invention, they are not intended to be exhaustive, but rather to be a guide, so that others skilled in the art may apply the invention to their varying applications in the most adept way.

In the drawing:

FIGURE 1 is a side elevation, partly in cross-section, of the connection of our invention as applied to a soldering iron prior to its assembly into the handle;

FIGURE 2 is a side elevation of the completely assembled unit; and

FIGURE 3 is an end view taken from lines 3-3 of FIGURE 2.

As shown in the drawings, the soldering iron comprises a conventional sheathed heater 26 having a centrally located heating element and a concentric metallic sheath spaced therefrom by a compacted insulating material. A soldering iron tip 11 is secured to the heater sheath in any suitable manner to provide eflicient heat transfer therebetween. When electrical power is applied between the sheath of heater 26 and terminal 27 of the heating element electrical current will flow through the heater to heat tip 11.

Referring more particularly to FIG. 1, we have shown an enlarged portion of our connecting device wherein an electrically conductive spring 13, which is preferably formed of tempered tin-coated steel strip of uniform width, is securely attached to the electric cord 12 by an oval type clamp 14. Inasmuch as the spring 13 projects above the cord 12, it will not pass through the bore 30 of the handle 28 for the cord 12 and a positive stop is effected to relieve any strain that would otherwise be transmitted from the cord 12 to the connecting device through electrical conductors 16 and 19 of the cord 12. Conductor 16 is inserted through a pre-formed hole 17 in electrically conductive spring 13 and is electrically connected, as by soldering, to the spring 13 at 18.

Conductor 19 also extends through a similar opening 20 in a similar electrically conductive spring 21 and is soldered in a similar manner at 22.

As shown in FIGS. 1 and 2, spring 13 has its free end pre-formed in the shape of an elongated U. Each leg 13b of this U-shaped portion is provided with an aperture 25 to receive the heater sheath 26 of the soldering tip 11.

Spring 21, which is also preferably formed of a tempered tin-coated steel strip, has its free end also formed in the shape of a U. As shown in FIG. 1, when springs 13 and 21 are in their relaxed positions, the axis of the U-shaped free end of spring 21 is aligned with the openings 25 of spring 13 so that it is positioned to receive the heater terminal 27. A11 insulated rivet 24 secures springs 13 and 21 to spacer 15 which is formed of an insulating material.

The handle 28, which is slideably positioned on the electric cord 12, has a hollow bore 29 to receive the spring assembly. A bore 30 of a slightly larger diameter than the electric cord 12 is located in the butt of the handle 28 and slideably receives the electric cord 12.

In FIG. 1, the spring assembly and the soldering tip are shown in an assembled position. It will be noted that the sheath 26 of the tip 11 is positioned in apertures 25 of spring 13. As will be apparent, it is desirable that the relaxed position of spring 13 is one in which the legs 13b of the U-shaped portion of the spring are slightly spread apart from their position when assembled with the tip. This will assure that the edges of the apertures 25 will tightly engage the sheath 26' of the heater to mechanically retain the assembly together during the assembly and disassembly process.

In a like manner, it is desirable that the relaxed position of the Ushaped portion of the spring 21 should be such that the legs of the U-shaped portion are closer together than the position they will assume when assembled with the terminal 27 of the heater so that they will tightly engage terminal 27 upon assembly.

It will be readily apparent that in order to assemble the unit, the heater sheath 26 is inserted through the apertures 25 and the terminal 27 is pushed into the U- shaped end of the conducting spring 21. If in the relaxed position of the U-shaped spring 13, the legs 13b are slightly spread apart from their position when assembled with the tip 11, it will of course be necessary to slightly compress the U-shaped portion of spring 13.

The unit shown in FIG. 1 is then pushed into the hollow bore .29 of handle 28 to a completely assembled position as shown in FIG. 2. When achieving this last step of the assembly, as will be noted, the springs 13 and 21 are firmly attached to the heater sheath 26 and terminal 27 respectively, thus assuring excellent electrical connections. The diameter of the hollow bore 29 of handle 28 is dimensioned so as to contact the free end 13a of the spring 13, as best shown in FIG. 3, as well as the opposite end 13d of the spring 13, to apply a force biasing the spring 13 against heater sheath 26.

In addition, the edges of the closed end of the U- shaped portion of spring 13 engage the surface of the bore 29 of the handle, as best shown in FIG. 3. It will be apparent that the contact of 1311, 13c and 13d with the bore of the handle will produce a leverage for applying or increasing the pressure securing the sheath 26 of the tip 11 in the spring assembly. Thus the contact between the spring 13 and the bore of the handle 29 serve to center the sheath 26 of the soldering tip 11 within the handle; to retain it in the handle due to the friction between the handle and the spring 13; and, because of the resiliency of the free end 13a of the spring 13, to resiliently support the tip 11 within the handle. The resiliency of the support of tip 11 is highly desirable, particularly in use on work of a delicate nature. Also, in the event the soldering iron is dropped, the resiliency of the support would minimize the likelihood of, and the extent of, damage resulting to the tool. The areas of the spring 13, which are in contact with the bore of handle 28, are also relatively small and, therefore, provide a poor heat transfer path from tip 11 and handle 28.

It will also be apparent that the angle between the U- shaped portion 21a and the straight portion 21b of spring 21 is reduced upon assembly of the tip 11 within handle 28 to apply contact pressure between spring 21. and terminal 27.

Although we have shown in the drawing and described a particular embodiment of our invention above in connection with a soldering iron, it will be understood by those skilled in the art that the invention may also be used in connection with other types of electrical hand tools. Moreover, modifications of our invention as, for

example, the use of other than U-shaped spring configura- 1 tions, will occur to those skilled in the art. It should be understood, therefore, that our invention is not limited to the particular arrangement shown, and we intend in the appended claims to cover all modifications which do not depart from the spirit and scope of our invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. An electric soldering iron comprising a handle having a hollow bore in one end thereof, an electrically heated soldering iron tip comprising a sheathed heater having a centrally located heater terminal projecting from one end thereof, and a spring assembly for removably supporting the heater tip in the handle and for conducting electrical power to the heater tip, said spring assembly comprising a first U-shaped spring member apertured to receive the sheathed heater and engaging the outer surface of the sheathed heater and the inner surface of the hollow bore of the handle for resiliently retaining and positioning the sheathed heater within the handle, and a second spring member electrically insulated from said first spring member and having a U-shaped portion axially aligned with the apertures of the first spring member to provide an electrical connection with said terminal.

2. An electric soldering iron comprising a handle having a hollow bore in one end thereof, an electrically heated soldering iron tip comprising a sheathed heater having a centrally located heater terminal projecting from one end thereof, and a spring assembly for removably supporting the heater tip in the handle and for conducting electrical 5 power to the heater t1p, said sprmg assembly comprising a first spring member having depending leg portions apertured to receive the sheathed heater and engaging the outer surface of the heater sheath and other portions engaging the inner surface of the hollow bore of the handle for frictionally retaining and positioning the sheathed heater within the handle and a second spring member electrically'insulated from said first spring member and having a portion axially aligned with the apertures of the first spring member to provide an electrical connection with said terminal.

3. For use with an electrically powered hand tool having a metallic outer sheath member for supporting the tip of the tool and a centrally located terminal extended from the end of the said sheath member, a handle and connector assembly for supporting said tool comprising a hollow handle, and a spring assembly, said spring assembly comprising a first U-shaped spring member apertured to receive the outer surface of said sheath member for mechanically supporting it within the handle and a second spring member electrically insulated from said first spring member and having a U-shaped portion axially aligned with the apertures of the first spring member to provide an electrical connection with said terminal.

4. An electric soldering iron comprising a handle having a hollow bore in one end thereof, an electrically heated soldering iron tip comprising a sheathed heater having a centrally located heater terminal projecting from one end thereof, and spring means for removably supporting the heater tip in the handle and for conducting electrical power to the heater tip, said spring means comprising a first spring member having depending leg portions apertured to receive the sheated heater and engaging the outer surface of the heater sheath and other portions engaging the inner surface of the hollow bore of the handle for frictionally retaining and positioning the sheathed heater within the handle and a second spring member electrically isolated from said first spring member and having a portion axially aligned with the apertures of the first spring member to provide an electrical connection with said terminal.

References lirted in the file of this patent UNITED STATES PATENTS 2,059,605 Powell Nov. 3, ,1936 2,180,665 Bruggerman Nov. 21, 1939 2,422,265 Squires June 17, 1947 2,435,654 Pleva Feb. 10, 1948 2,505,625 Nordstrom Apr. 25, 1950 2,552,193 Lennox May 8, 1951 2,747,074 Finch May 22, 1956 2,768,275 Kuhn et al. Oct. 23, 1956 2,845,518 Teicheire July 29, 1958 FOREIGN PATENTS 17,749 Great Britain Nov. 24, 1894 of 1894 547,198 Great Britain Aug. 18, 1942 

